The article outlines an approach to studying the Russian-speaking diaspora in the Mongolian People’s Republic in the twentieth century as a mestizo community. Formed by different categories of migrants from the Russian Empire, this community demonstrated a large number of intermarriages with Mongols and representatives of the Chinese diaspora. The first Russian colonists were Old Believers and Cossacks. After the Civil War their ranks were swelled by refugees and later, in the 1940s, by quite a few former GULAG prisoners who fled the two large Soviet camps established on the Mongol territory. These culturally and socially very different groups of people were homogenized by their disenfranchised status and cultural exclusion, and developed a common self-identification as “local Russians” (mestnorusskie).